As the human's demands on smart lives gradually increase, the data processing capability becomes more important. Generally, the global energy consumption in data processing reaches hundreds of billions or even several trillion kilowatt-hours per year. A large data center occupies an area of several tens of thousands of square meters. Consequently, it is important to develop a data center with high efficiency and high power density.
The key component unit of the data center is a server. A main board of the server is usually equipped with central processing units (CPUs), chipsets, memories, data processing chips, a power supply and the essential peripheral components. These electronic components are installed on the main board. Moreover, the data center comprises plural servers. Generally, a bus bar is shared by some servers. The plural servers all receive electric power from the bus bar.
FIG. 1 schematically illustrates the first conventional architecture of a rack in a data center. In a rack 5 of a data center, a bus bar 51 is shared by plural servers 50. The voltage of the bus bar 51 is a 12V-DC voltage. The 12V-DC voltage is transmitted to the input terminal of the circuit board of each server 50. Moreover, the 12V-DC voltage is further transmitted to a point-of-load (POL) conversion module 52 through traces (e.g., copper lines) and then transmitted to the load 53 of the corresponding server 50. For saving the resources of the main board, the main board usually has no extra copper layers to form the traces. That is, the resistance of the traces Rtrace on the main board is usually high. The high trace resistance Rtrace results in obvious power transmission loss. Moreover, since the 12V-DC voltage provided to the bus bar 51 is low, the current flowing through the bus bar 51 is relatively higher. For example, the current of a 1.2KW-server is up to 100 A when the input voltage is 12V. Since the integration of the main board is different, the efficiency of the main board will decrease by about 0.5%˜2%. As the demands on the data processing capability of the main board increase, the problem of efficiency reduction becomes more serious. Moreover, the POL conversion module 52 usually comprises a 12V-buck converter for receiving the 12V-DC voltage. As known, the 12V-buck converter is not suitable for development of the high-integration servers. As mentioned above, the main board of the server is usually equipped with CPUs, chipsets, memories, data processing chips, a POL conversion module and the essential peripheral components. As the processing capability of the server increases, the number and the volume of the processing chips increase. Under this circumstance, the layout space and the power consumption increase. It is important that the POL conversion module for these chips should have higher efficiency and smaller volume. However, since the working voltages of these chips are usually lower than 2V or even lower than 1V, the voltage difference between the input terminal and the output terminal of the 12V-buck converter is very large. That is, it is difficult to achieve both purposes of high efficiency and small volume. Moreover, the 12V-buck converter usually uses high-voltage MOS components (e.g., 25˜30V). Since the working efficiency is usually several kHz, the conventional POL conversion module is not suitable for the development of the high speed data processing chip.
FIG. 2 schematically illustrates the second conventional architecture of a rack in a data center. For solving the above drawbacks, it is necessary to increase the voltage of the bus bar 51. For example, if the voltage of the bus bar 51 increases to 48V, the power loss will decrease by about 1/16. If the voltage of the bus bar 51 increases to 400V, the efficacy of the power loss reduction is more obvious. As shown in FIG. 2, the voltage of the bus bar 51 increases to 48V. Moreover, the input terminal of the circuit board of each server 50 is connected with a DC/DC converter 54. By the DC/DC converter 54, the 48V is converted into 12V-DC voltage. The 12V-DC voltage is further transmitted to the POL conversion module 52 through traces and then transmitted to the load 53 of the corresponding server 50.
Since the voltage of the bus bar 51 increases to 48V and the 48V is converted into 12V-DC voltage by the DC/DC converter 54, the drawbacks of using the 12V-DC voltage also exist. In additional, some new problems occur. For example, the high trace resistance Rtrace also results in obvious power transmission loss. Moreover, since the POL conversion module 52 also uses the 12V-buck converter, it is difficult to achieve both purposes of high efficiency and small volume and the conventional POL conversion module is not suitable for the development of the high speed data processing chip. Moreover, since the volume of the DC/DC converter 54 is bulky, it is difficult to install the DC/DC converter 54 on the circuit board. For installing the DC/DC converter 54, it is necessary to increase the size of the circuit board, which is detrimental to the miniaturization of the server.
Therefore, there is a need of providing an improved power module in order to overcome the above drawbacks.